Hybrid pad system

The present disclosure relates generally to a hybrid pad system, which may be in the form of a launch pad and/or a stowage pad, and more particularly to launch pads and stowage pads that may be utilized within missile launching systems to maintain missile alignment.

Launch pads and stowage pads may be used in missile launching systems to maintain missile alignment, mitigate shock and vibration, and/or provide lateral support to the missile during launch. In some instances, a plurality of pad units containing buckled (e.g., chevron-shaped) struts may be used to perform these functions. Due to the segmented nature of the pad units and the curved annular space, however, a desirable plateau characteristic is considerably diminished when the overall pad row (ring level) force/deflection characteristics are developed. Accordingly, an improved system and method would be welcomed in the technology.

Aspects and advantages of the present disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the present disclosure.

According to some aspects of the present disclosure, a hybrid pad system positioned between a missile and a launch tube. The hybrid pad system includes an outer sheet and an inner sheet spaced from the outer sheet. A resilient structure is positioned between the outer sheet and the inner sheet. The resilient structure includes one or more web regions and one or more restoration regions.

According to some aspects of the present disclosure, a method of manufacturing a hybrid pad system includes placing an injector mold plate of a mold assembly in a defined position relative to an ejector mold plate to define an injection mold. The method also includes forming an outer sheet, an inner sheet, one or more web regions of a resilient structure, and one or more restoration regions of the resilient structure by injecting a material between the injector mold plate and the ejector mold plate.

According to some aspects of the present disclosure, a hybrid pad system positioned between a missile and a launch tube. The hybrid pad system includes an outer sheet and an inner sheet spaced from the outer sheet. A web region is positioned between the outer sheet and the inner sheet. A restoration region is positioned between the outer sheet and the inner sheet and tangentially offset from the web region. A support is operably coupled with the inner sheet.

These and other features, aspects, and advantages of the present disclosure will be further supported and described with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present technology.

Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.

In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. Furthermore, any arrangement of components to achieve the same functionality is effectively “associated” such that the functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected” or “operably coupled” to each other to achieve the disclosed functionality, and any two components capable of being so associated can also be viewed as being “operably couplable” to each other to achieve the disclosed functionality. Some examples of operably couplable include, but are not limited to, physically mateable, physically interacting components, wirelessly interactable, wirelessly interacting components, logically interacting, and/or logically interactable components.

Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” “generally,” and “substantially,” is not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or apparatus for constructing or manufacturing the components and/or systems. For example, the approximating language may refer to being within a ten percent margin.

Moreover, the technology of the present application will be described in relation to exemplary embodiments. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Additionally, unless specifically identified otherwise, all embodiments described herein will be considered exemplary.

As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition or assembly is described as containing components A, B, and/or C, the composition or assembly can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

In general, the present subject matter is directed to a hybrid pad system that may be disposed between a payload (e.g., a missile) and a surrounding housing (e.g., a launch tube).

In some examples, the hybrid pad system can include an outer sheet and an inner sheet spaced from the outer sheet. A web region can be positioned between the outer sheet and the inner sheet. A restoration region can be positioned between the outer sheet and the inner sheet and tangentially offset from the web region. A support can be operably coupled with the inner sheet. In some cases, the support can be configured as a preformed material formed from at least one of a metallic material, an elastomeric material, a polymeric material, or a synthetic material. Additionally or alternatively, the support can be configured as a thicker region along the inner sheet compared to the one or more web elements. Moreover, the restoration regions and/or the web regions can be altered about the perimeter to attain defined restoring/damping responses in specific directions.

The hybrid pad system provided herein can increase the performance and/or reduce a manufacturing cost of the shock/stowage/launch pad system (also known as lateral support pads). Moreover, the hybrid pad system provided herein can increase a range of viable solutions to meet new and more challenging design constraints, such as increased shock mitigation, lower peak contact forces (such as highly local forces imposed on the payload skin by the hybrid pad system provided herein architecture), and greater cross-flow capability during launch. The design freedom offered by the ability to blend disparate elements within the stabilizing resilient structure can also enable a multi-function hybrid pad system that integrates additional functionality and performance.

Moreover, the hybrid pad system provided herein can combine some of the benefits of a sling-type pad with a compression-type pad to enable a broader range of design attributes to enhance the performance of the hybrid pad system used to isolate and protect payloads in undersea and surface launch launcher systems during storage, stowage, transportation, and/or launch. In some cases, the hybrid pad system utilizes elements of various other pad architectures but can reduce the number of tension webs so that a greater or lesser portion of the annular space can be occupied by buckled strut or other restoring elements that act on the hoop in a “by design” combination of compression, shear, and tensile force vectors.

The hybrid pad system provided herein can also be applied to any broadly similar shock isolation or cushioning application. The hybrid pad system architecture can combine the integrated support (e.g., hoop/belt architecture) and stabilizing tension webs of a sling pad with a buckled strut or other restoring elements to enable a stable, load-spreading hybrid pad system that maximizes performance compared to known solutions. The use of compression elements within the sling pad architecture generally allows a more rapid rise to a desired plateau pressure and provides increased tunability to achieve a desired force/deflection curve performance.

Referring now to, a payload assemblycan include a payload, a surrounding housingseparated from the payloadand configured to support the payload, and a hybrid pad systempositioned between the payloadand the surrounding housing. For instance, the payloadmay be in the form of a missile, and the surrounding housingmay be in the form of a launch tube with the hybrid pad systempositioned between the launch tube and the missile. However, it will be appreciated that the hybrid pad systemprovided herein may be used in any other manner without departing from the scope of the present disclosure.

As illustrated in, the hybrid pad systemcan include an outer sheetand an inner sheet, which may be a cylinder, a truncated cylinder, or any other geometry. In some examples, the outer sheetcan define an outer perimeter portion of the hybrid pad system. In some cases, the outer region of the outer sheetmay be adhered to or otherwise coupled with surrounding housing, such as a launch tube. The inner sheetcan define an inner perimeter portion of the hybrid pad system. In various cases, the inner sheetmay contact the payload. For instance, the inner sheetmay be compressively retained, adhered to, or otherwise contact the payload. The outer sheet, the inner sheet, and/or the resilient structuremay be elastically deformable to maintain alignment of the missile within the launch tube, mitigate shock and vibration, and/or provide lateral support to the missile during launch and/or at any other time.

In examples in which the outer sheetand the inner sheetare cylindrical, the outer sheetand the inner sheetmay be coaxial with one another about a common axis. In such instances, the inner sheetmay be separated from the outer sheetto define a thickness of the resilient structuretherebetween. In some examples, such as the ones illustrated in, the resilient structurecan include one or more structural elements. In some examples, the structural elementscan include one or more web elementswithin a web regionthat may provide both circumferential stability (e.g., prevent slewing) and/or a restoring force that acts through the inner sheet. Additionally or alternatively, the structural elementscan include one or more restoring elements, such as a buckled strut, within a restoration region. The web regionsand the restoration regionsmay be interspersed with one another within the resilient structure. In various cases, a radial width of the web regionrelative to the common axismay be common or varied from a radial width of the restoration regionrelative to the common axis. Moreover, a radial width of a first web regionrelative to the common axismay be common or varied from a radial width of a second web regionrelative to the common axis. Likewise, a radial width of a first restoration regionrelative to the common axismay be common or varied from a radial width of a second restoration regionrelative to the common axis.

In some examples, the web elementsmay contact one or more of at least one additional web element, the outer sheet, and/or the inner sheet. For instance, one or more of the web elementsmay be configured to be integrally formed and/or otherwise operably coupled with the outer sheetat a first contact pointand the inner sheetat a second contact point. In some cases, the first contact pointand the second contact pointmay be circumferentially (or tangentially) offset from one another about the common axisof the outer sheetand the inner sheetby a first tangential angle θ. In addition, a first web elementmay intersect a second web elementat an intersection pointthat may be between the first contact pointand the second contact point. In some instances, the intersection pointcan be generally tangent (or close to tangent) with a center section of the inner sheet(slightly inboard in the depicted example). In addition, in various examples, the intersection pointmay be a radial midpoint between the first contact pointand the second contact point. The web elementsmay be configured to create an efficient hybrid pad systemthat utilizes a web element length that can minimize and/or reduce peak strain for a defined stiffness and stroke.

In several examples, the restoring elementsmay be configured as struts, such as buckled (e.g., chevron-shaped) struts, extending between the outer sheetand the inner sheet. In various examples, one or more of the strutsmay be configured to be integrally formed and/or otherwise operably coupled with the outer sheetat a third contact pointand the inner sheetat a fourth contact point. In some cases, the third contact pointand the fourth contact pointmay be circumferentially (or tangentially) offset from one another about the common axisof the outer sheetand the inner sheetby a second tangential angle θ. In some cases, the second tangential angle θmay be zero (0) degrees. In several examples, the second tangential angle θmay be less than the first tangential angle θ. However, it will be appreciated that the second tangential angle θmay be greater than or equal to the first tangential angle θwithout departing from the teachings provided herein. In some cases, the buckled (e.g., chevron-shaped) strutsmay be divided into two groups within each restoration region. In various examples, a first groupof one or more buckled strutsis oriented in a first direction, and a second groupof one or more buckled strutsis oriented in a second, opposing direction with a knee sectionof the buckled strutsfacing towards each other. In some instances, a distance between the first groupand the second groupmay be greater than a distance between a first strutand a second strutwithin at least one of the first groupor the second group.

In various examples, the knee sectioncan be positioned between a pair of opposing leg sections. In some cases, the knee sectioncan be configured to further control a bending movement of the strutwhen force is applied thereto. For instance, the knee sectionmay have a semicircular shape to encourage the bending movement of the knee sectionin a defined manner, which may occur before the bending movement of the opposing leg sections. In various examples, first and second hinges may be defined where the leg sections transition into the outer sheetand the inner sheet. In several examples, the knee sections may be radially offset in an inboard and/or outboard manner (e.g., offset from a center location between the outer sheetand the inner sheet).

Moreover, in various examples, each of the struts may define a strut angle between the opposing leg sectionsof each strut. It will be appreciated that the strut angle, a thickness of the inboard leg section compared to an outboard leg section, and/or a location of the knee section may be modified based on the various design constraints. Each of these modifications is possible as the strutsdescribed herein can operate in a circumferentially larger system, and operate in a broader displacement space (e.g., the strutscan be compressed, sheared, and put in tension). Thus, the hybrid pad systemprovided herein offers tuning capability.

In some instances, the pressure deflection curves of the chevron strut design can be characterized as initially pressure rises sharply from small deflections, then the pressure remains generally constant for an appreciable amount of deflection, and finally as the strutsbegin to fall flat or bottom out the pressure rises sharply with small deflections. Thus, the force/deflection characteristics of these strutshave a defined characteristic plateau which allows a determined amount of lateral excursion at a relatively constant force. In some cases, the constant force may be a maximum permitted payload skin load in the case of a missile launcher.

In various examples, the hybrid pad systemmay include a support. For example, the supportmay be operably coupled with the outer sheet, the inner sheet, and/or the resilient structureof the hybrid pad systemand may extend approximately an axial height of a perimeter of the inner sheet. In some examples, the supportmay be configured as an inner hoop that is operably coupled with the inner sheet, such as by embedding the supportwithin the inner sheet. In some cases, the supportmay be operably coupled (directly or indirectly) with the outer sheet, the inner sheet, and the resilient structurethat, in combination, work largely in tension. In various examples, the hybrid pad systemmay be free of a supportbased on the payload assembly configuration, with the outer sheet, the inner sheet, and/or the resilient structureproviding a sufficient strength/modulus to support the payload. In some instances, an undersea-based payload assemblymay include the support while a surface launch payload assembly, where the hybrid pad systemis configured to fly out with the payloadand is discarded may include the support. Moreover, the payload assembly may include any number of hybrid pad systemswithout departing from the teachings provided herein. Further, in various examples, the supportmay be positioned within and/or otherwise operably coupled with any other component of the hybrid pad system. For example, the supportmay be positioned within and/or otherwise operably coupled with the outer sheetand/or any other component. The hybrid pad systemprovided herein can increase a hybrid pad system footprint on the payloadand engage more of the hybrid pad system material to resist deflection and generate net restoring force. These attributes can lower peak contact forces on the payloadand decrease peak and average strains in the hybrid pad system.

It will be appreciated that the support size, material, and modulus can be altered to fine-tune the hybrid pad system force/deflection curves. The ability to add various supports with the tension resilient structure, along with the ability to alter various parts of the hybrid pad systemcan increase the range of viable hybrid pad system materials (resulting from lower peak strains and simplified mold architecture), which, in turn, can expand the viable design space.

In some instances, the supportmay have a higher tensile modulus (or a lower tensile modulus) than the inner sheet, which may be accomplished by forming a thicker region along the inner sheetcompared to the one or more web elementsand/or operably coupling an additional component (any structure that is continuous or non-continuous and formed from a material that is varied from the material forming the inner sheet) to the inner sheet. In instances in which the supportis an additional component, the supportmay be insert-molded with the outer sheet, the inner sheet, and/or the resilient structure. Additionally or alternatively, the supportmay be later attached or otherwise coupled with the outer sheet, the inner sheet, and/or the resilient structure. In various examples, the support, which may be in tension, is generally slightly larger than a perimeter of the payloadand, thus, applies a sling load to an arc, which may be 180 degrees or more of the perimeter of the payloadon a compression side with the sling load being created by the sum of the compression, shear, and tension loads generated within the resilient structure. In some cases, a slight excess circumference of the supports may end up on a tension side, thus the inner sheetmay deform from a cylinder to an egg shape (or any other shape) as displacement increases, and a separation regionmay be created on the tension side.

In various examples, such as the example of, the hybrid pad systemcan retain a tensile hoop of the inner sheet, which can combine with the tension webs to prevent slewing within the hybrid pad systemand reduce contact pressure on the payload. Moreover, the hybrid pad systemcan retain a percentage of a sling pad tension webs for stability and load-spreading while the restoring elements, such as buckled struts, can improve initial stiffness compared to a sling pad. Moreover, the percentage of web elementsversus other restoring elementscan be a tunable feature based on the design constraints of the hybrid pad system. Furthermore, the supportcan unite the hybrid pad systemcircumferentially so that each of the web elementsand the restoring elementscan provide a restoring force when a force is applied to the payload.

In various examples, the inner sheetand/or the supportcan bear against the payload. As such, the inner sheetand/or the supportcan include a layerthereon that is configured to reduce an amount of friction between the payloadand the inner sheetand/or the support. For instance, the layermay include a polytetrafluoroethylene material, and/or any other material. In some instances, the layermay be configured to exhibit nonstick, waterproof, noncorrosive, and/or nonreactive characteristics. In some cases, the hybrid pad systemmay experience quality check and/or other testing before end usage within the payload assembly. Due to the deformation characteristics exhibited by the hybrid pad systemprovided herein, the layermay have less degradation during quality assurance (QA) testing and operation when compared to legacy pad systems that include a layerthereon.

In several examples, the hybrid pad system, or portions thereof, can be formed from an energy-absorbing material that behaves in a rate-independent hyperelastic manner wherein its permanent set is minimized so that the energy-absorbing material maintains consistent force-displacement characteristics over a wide range of displacements while remaining substantially fully recoverable. Hyperelastic materials have the ability to do work by absorbing kinetic energy transferred from impact through an elastic deformation with little viscous damping, heat dissipation (from friction forces), or permanent deformation (i.e., permanent set). This mechanical energy can then be returned to nearly its original shape (e.g., about 100%) allowing the components to return to their original configuration before impact with negligible strain.

Further, the hyperelastic material can behave in a hyperelastic manner under dynamic loadings of high strain rates of up to at least 900-1000 s. The hyperelastic material can allow for movement of the payloadrelative to the surrounding housingand also allow for the recovery of the hybrid pad systemto its original geometry, or a generally similar geometry in which the deformation is maintained below a defined threshold (e.g., 10%). The hyperelastic material can have non-linear elastic responses when deformed from its original geometry. It will be appreciated that the hyperelastic material may be in the form of a thermosetting or thermoplastic urethane, and/or any other practicable material that can exhibit elastic, superelastic, or hyperstatic characteristics.

In various examples, the hybrid pad systemprovided herein may generate a generally uniform loading on the payload. However, in some cases, the hybrid pad systemmay create more of a rising rate force/deflection curve rather than a ramp-plateau characteristic. In some instances, this characteristic may be improved by creating a pad systemthat can be pre-loaded during installation. In such instances, the hybrid pad systemmay be cast/fabricated in two parts. For instance, a first part may include the outer sheetwhile the second part includes the remaining components of the hybrid pad system, which can include the inner sheetand/or the resilient structure. Moreover, in several examples, the second part may be cast, molded, and/or additively manufactured such that the resilient structuremay have a non-stretched length that is less than a default distance between the outer sheetand the inner sheet. In such instances, the resilient structuremay be stretched from its default length to attach (by any number of methods) to the outer sheetso that tension is generated in the resilient structureupon installation. Accordingly, the resilient structuremay be pre-stretched so that the resilient structuremay act to create a quicker ramp up of the force/deflection curve of the hybrid pad systemwhen displaced and create a plateau by transitioning into the hyper-elastic material zone as displacement increases.

In some cases, the hybrid pad system, or portions thereof, may be formed by staging a casting to partially fill a mold, then re-arrange or introduce new mold sections, then complete the casting. For instance, as provided herein, the hybrid pad systemmay be cast from thermosetting elastomers, as these materials are well-vetted for various launcher requirements. One of the characteristics of these materials is that they are cast and then go through various post-casting processes, such as initial cure before demolding, then additional curing over some sort of time/temperature schedule. As such, by utilizing a secondary “staged” casting within a short time window, the resultant casting of the hybrid pad systemmay be robust, as if it were all cast at once.

Referring now to, in some cases, the hybrid pad systemmay include a tolerance regionthat may be operably coupled with and/or integrally formed with the outer sheet, the inner sheet, and/or any other component of the hybrid pad system. At times, a certain amount of tolerance build-up between the payloadand the hybrid pad systemand/or the hybrid pad systemand the surrounding housingmay tend to loosen a mating relationship between the various components of the payload assembly. The tolerance regionmay compensate for this extra tolerance and/or increase the gripping force of the hybrid pad systemto the payloadand/or the surrounding housing. As shown, the tolerance regioncan include extensionsthat can extend inwardly (towards the common axis) from the inner sheet. Additionally or alternatively, the tolerance regioncan include extensionsthat can extend outwardly (away from the common axis) from the outer sheet. In various examples, the tolerance regionmay be configured to not add extra thickness to the fully compressed stack-up of the hybrid pad system. In such examples, the tolerance regionmay be configured as “ripples” or “corrugations” in the inner sheetrather than features that combine to add thickness to the inner sheetand thus to the fully compressed stack height. It will be appreciated that, in some instances, the tolerance regionmay also generally allow the supportto be slightly larger than the diameter of the payload. Such a configuration may avoid high encapsulation forces or friction loads while still allowing the hybrid pad systemto act in a sling-like manner. Additionally or alternatively, the tolerance regionmay be configured as “ripples” or “corrugations” in the outer sheetrather than features that combine to add thickness to the outer sheet.

Referring now to, a displacement (illustrated by arrowin) of the payloadand the hybrid pad systemwithin the surrounding housingis shown. Specifically,illustrates the payloadand the hybrid pad systemwithin the surrounding housingbefore the payloadexperiences the displacement with the initial axis labeled as.illustrates the payloadand the hybrid pad systemwithin the surrounding housingwith a displacement of the payloadat a first displacement with the initial axis of the payloadlabeled asand the payload axis at the first displacement labeled as.illustrates the payloadand the hybrid pad systemwithin the surrounding housingwith the displacement of the payloaddisplaced at a second displacement that is greater than the first displacement with the initial axis of the payloadlabeled asand the payload axis at the second displacement labeled as. The arrowindicates the direction of the displacement of the payload.

In the examples illustrated in, the outer sheetmay be at least partially adhered to or otherwise coupled with a surrounding housing. As the payloadis displaced, the components of the hybrid pad systemmay deform causing a separation distanceis defined between the payloadand a separation regionof the hybrid pad systemas one or more components of the hybrid pad systemare deformed. In general, the separation regioncan be controlled by the modulus of the supportand the relative stiffness of the supportthat may be embedded and/or attached to the inner sheetcompared to the cumulative tension/shear forces being generated by the resilient structure. For example, a first segmentof the resilient structureis extended, and a second segmentof the resilient structureis compressed when the payloadis displaced, which are indicated by the deformation from the initial shape, as shown in, of the tension elements. In addition, the supportcan transfer tension within the resilient structureinto a uniform sling load in a compression zone. In some instances, the supportmay reduce the separation distanceby distributing the load along the circumference of the hybrid pad system.

In response to the deformation of the hybrid pad system, the resilient structurepositioned between the outer sheetand the inner sheetcan work in compression and tension to resist deflection of the payloadand generate a net restoring force. In some cases, these attributes can dramatically lower peak contact forces on the payloadand decrease peak and average strains in the hybrid pad system. As provided herein, the amount of restorative force generated by the hybrid pad systemcan differ based on the materials used to form the hybrid pad system, the resilient structure, the thickness of the outer sheet, and the thickness of the inner sheet, among other factors.

Referring now to, a displacement (illustrated by arrowin) of the payloadand the hybrid pad systemwithin the surrounding housingis shown. Specifically,illustrates the payloadand the hybrid pad systemwithin the surrounding housingbefore the initiation of the displacement having an initial axis of the payloadlabeled as.illustrates the payloadand the hybrid pad systemwithin the surrounding housingwith the displacement at a first displacement with the initial axis of the payloadlabeled asand the payload axis at the first displacement labeled as.illustrates the payloadand the hybrid pad systemwithin the surrounding housingwith the displacement at a second displacement that is greater than the first displacement with the initial axis of the payloadlabeled asand the payload axis at the second displacement labeled as. An arrowindicates the direction of the force being applied to the payload.

In some examples, such as the one illustrated in, the resilient structurecan include a respective web elementthat can form a tension web within each respective web regionand/or one or more restoring elements(such as the strutsdescribed herein) within each respective restoration region. As illustrated, a first restoration regioncan include a first set of a defined number (e.g., one or more) of strutsand a second restoration regioncan include a second set of a defined number (e.g., one or more) of struts, which may be varied or common with the first set of struts. In various examples, the knee sectionsof the strutswithin the first set of strutsand/or the second set of strutscan be configured to face towards each other, away from each other, and/or in any other direction.

In the example shown in, the outer sheetmay be at least partially adhered to or otherwise coupled with a surrounding housing. For instance, the outer sheetmay define attached sectionsin which the outer sheetand the surrounding housingare adhered or otherwise attached to one another. In some instances, the attached sectionsmay be generally aligned with the web regionsof the resilient structure. In addition, the outer sheetmay define unattached sectionsin which the outer sheetand the surrounding housingare not adhered to or otherwise attached to one another. In some instances, the unattached sectionsmay generally be aligned with the restoration regionsof the resilient structure. In some cases, by having intermittent attached sectionsand unattached sections, the use of a high modulus support and stiff compressive elements may be utilized while minimizing peak strains that would otherwise occur with straightening and stretching of the buckled struts. Additionally or alternatively, in various examples, straightening the strutsmay not produce a desired ramp-plateau characteristic, so if there is too much strut straightening the overall force/deflection curve of the hybrid pad systemstrays from the desired ramp-plateau behavior.

In the examples shown in, as the payloadis displaced, the components of the hybrid pad systemmay deform causing a separation distanceis defined between the payloadand a separation regionof the hybrid pad systemas one or more components of the hybrid pad systemare deformed. For example, a first segmentof the resilient structureis extended, and a second segmentof the resilient structureis compressed when the payloadis displaced. In addition, the supportcan transfer tension within the resilient structureinto a uniform sling load in a compression zone. In some instances, the supportmay reduce the separation distanceby distributing the load along the circumference of the hybrid pad system. Further, in some cases, the unattached sectionsof the hybrid pad systemcan deform and create an additional separation space.

In response to the deformation of the hybrid pad system, the hybrid pad systemcan provide a collection of restoring web elementsin the form of the resilient structurepositioned between the outer sheetand the inner sheetthat can work in tension to provide stability against slewing, resist deflection of the payloadand/or generate a net restoring force. In some cases, these attributes can dramatically lower peak contact forces on the payloadand decrease peak and average strains in the hybrid pad system. As provided herein, the amount of restorative force generated by the hybrid pad systemcan differ based on the materials used to form the hybrid pad system, the resilient structure, the thickness of the outer sheet, and the thickness of the inner sheet, among other factors.

Moreover, in some cases, the deformation may cause various components to deform from its non-displaced geometry. For instance, as the separation distance increases, the shear and tension portions of the resilient structuremay resist deformation, and thus, deform or stretch the inner sheet(with or without the support) into a slight egg shape that creates tension in the lateral regions of defines the inner sheet with respect to the orientation shown in.

Referring now to, in some examples, the hybrid pad systemmay further include a sealing regionthat can control and/or affect eject gas flow during an eject event. In some examples, such as those illustrated in, the sealing regionmay be positioned between the inner sheetand the outer sheetand may contact an axial end portion of the resilient structure. Additionally or alternatively, in some cases, such as the example illustrated in, the sealing regionmay be separated from the resilient structurebetween the inner sheetand the outer sheet.

As illustrated in, the sealing regionmay extend internally of the outer sheet, the inner sheet, and/or the resilient structurein an axial direction to operably couple or seal the outer sheetwith the inner sheet. As shown, the sealing regionmay define a sealing heightin the axial direction that defines a volume between the inner sheetand the outer sheet, which may be separated from the resilient structureby the sealing region. In the example illustrated in, when present, eject gases may be separated from the resilient structuredue to the sealing region. In such cases, the presence of the eject gas within the sealing volume may alter a force-deflection curve of the hybrid pad system. As such, the design of the resilient structuremay be determined based on a combination of the resilient structure, the changes in characteristics based on the presence of the eject gas within the sealing volume, the support, and/or other factors. In some instances, when the sealing regionis positioned in a lower section of the hybrid pad system, an axial compression or axial buckling load may be created on the inner sheetof the hybrid pad system, such as during intervals when the sealing regionmay be pressurized by eject gases associated with a missile launch. Moreover, the hybrid pad systemmay include an embedded supportto mitigate or prevent local buckling.

As illustrated in, the sealing regionmay extend externally from the outer sheet, the inner sheet, and/or the resilient structurein an axial direction to operably couple or seal the outer sheetwith the inner sheet. As shown, the sealing regionmay define a sealing heightin the axial direction that defines a volume between the resilient structure and the sealing region. In some instances, the scaling height may be determined by the maximum radial displacement expected on the “tension side” (i.e., the “wide-gap” side) of the hybrid pad system. For instance, a length of the legsL and a length of the arcA of the sealing regionare sized to retain/allow a half-toroid (perhaps with shorter legsL) at the maximum gap. As such, as the gap increases from nominal due to radial displacement of the payload, the scaling regiondevelops a larger radius by “borrowing” some of the vertical lengths of the legsL (and the top of the sealing regionmoves downward axially compared to the nominal position). In some instances, if there was no vertical length of the legsL in the nominal position, the sealing regionmay flatten to a less desirable “flatter arc” shape that may increase stress in the sealing regionat that location. Conversely, on the narrow-gap side, the sealing regionis compressed, and the nominal radius of the half-toroid may be reduced, some of the length of the arcA then transitions into longer “vertical legs,” (as the sealing regionis constrained between the launcher housing() and the payload()). In some instances, the vertical legsL may be sized to permit a defined stress state for the sealing region(e.g., the size of the legsL and the size of the arcA are configured to allow a full semicircle half-toroid radius in each state).

In the example illustrated in, when present, eject gases may be disposed within the hybrid pad system, such as any open area between the inner sheetand the outer sheet. As such, the eject gas may be present within the resilient structure. In such cases, the presence of the eject gas may alter a force-deflection curve of the hybrid pad system. In such instances, the design of the resilient structuremay be determined based on a combination of the resilient structure, the changes to the resilient structurebased on the presence of the eject gas, the support, and/or other factors. In various examples, a more uniform load distribution in the hybrid pad systemmay be created when positioning the sealing regionas shown incompared to the sealing regionillustrated in. Moreover, the hybrid pad systemmay be free of a support, but may capture high-pressure eject gases and, thus, may be more likely to create more normal load and, consequently, axial friction on the payloadduring an eject event. As such, in instances in which this occurrence may be a concern for a particular launcher and payload, the inner sheet may define vent holesand/or the example shown inmay be utilized in an uppermost launcher seal location where pressures may be lower as a launcher may contain five or more seals, in some examples.